Around here (Wiltshire) there's been a clamp down on the use of unregistered motor vehicles on "green lanes" across the Plain, and there are several groups of volunteers who seem to make it their business to report people riding motorcycles etc on tracks and paths. These people are quite well up on the law and wouldn't hesitate to report someone if they saw it as an opportunity to get another wheeled vehicle off routes that they believe should only be walked or ridden on horseback, even if bikes are legally allowed.